Variable LZX window sizes

[wimlib] / src / lz77.c

diff --git a/src/lz77.c b/src/lz77.c
index 887b874506857251b2bda6c92809c3d008777222..049b322564e7b4e2cf2fbac1e17efe092411aee4 100644 (file)
--- a/src/lz77.c
+++ b/src/lz77.c
@@ -35,19 +35,10 @@
 
 #include <string.h>
 
-#define LZ_MIN_MATCH 3
-
 #define HASH_BITS      15
 #define HASH_SIZE      (1 << HASH_BITS)
 #define HASH_MASK      (HASH_SIZE - 1)
-
-#if LZ_MIN_MATCH == 2
-#      define HASH_SHIFT       8
-#elif LZ_MIN_MATCH == 3
-#      define HASH_SHIFT       5
-#else
-#error "Invalid LZ_MIN_MATCH"
-#endif
+#define HASH_SHIFT     5
 
 /* Hash function, based on code from zlib.  This function will update and return
  * the hash value @hash for the string ending on the additional input character
@@ -82,7 +73,7 @@ insert_string(input_idx_t hash_tab[], input_idx_t prev_tab[],
              const u8 window[], unsigned str_pos,
              unsigned hash)
 {
-       hash = update_hash(hash, window[str_pos + LZ_MIN_MATCH - 1]);
+       hash = update_hash(hash, window[str_pos + 2]);
        prev_tab[str_pos] = hash_tab[hash];
        hash_tab[hash] = str_pos;
        return hash;
@@ -291,21 +282,17 @@ lz_analyze_block(const u8 window[],
 
                        /* Do not insert strings in hash table beyond this. */
                        unsigned max_insert = window_size - params->min_match;
-#if LZ_MIN_MATCH == 2
-                       if (prev_len >= 3)
-#endif
-                       {
-                               prev_len -= 2;
-
-                               do {
-                                       if (++cur_input_pos <= max_insert) {
-                                               hash = insert_string(hash_tab, prev_tab,
-                                                                    window,
-                                                                    cur_input_pos,
-                                                                    hash);
-                                       }
-                               } while (--prev_len != 0);
-                       }
+
+                       prev_len -= 2;
+
+                       do {
+                               if (++cur_input_pos <= max_insert) {
+                                       hash = insert_string(hash_tab, prev_tab,
+                                                            window,
+                                                            cur_input_pos,
+                                                            hash);
+                               }
+                       } while (--prev_len != 0);
                        match_available = false;
                        match_len = params->min_match - 1;
                } else if (match_available) {